Fluid specimen cups are commonly used to collect and test fluid specimens for the presence or absence of specific “indicators” which show the presence of certain chemicals, hormones, antibodies or antigens associated with various physiological conditions and are commonly used for drug screening.
As disclosed in Cipkowski U.S. Pat. No. 5,976,895, preliminary testing or screening is often conducted by manually inserting the bottom end of a cartridge carrying a number of immunoassay-type chromatographic test strips into a cup to contact the liquid specimen with the sample pad on the strips. The use of multiple strips in a single cartridge can simultaneously conduct a panel of tests from a single specimen.
Unfortunately, the results of the test can be affected by the volume of fluid in the sample. In other words, the results in the Cipkowski device can be different depending on whether the cup is returned ⅓ full versus ⅔ full. Greater accuracy can be achieved by requiring the fluid sample to be within a narrow volume range. However, adjusting the volume of the specimen in a device like the one in Cipkowski must be done manually and therefore can be a difficult, time-consuming, and prone to inaccuracy. Such adjustment also carries a health risk for the person conducting the test and a contamination risk to the specimen or testing media.
Oftentimes, if an initial screening test comes back positive for drug use, the conductors of the test may seek to confirm the result by conducting a more rigorous and accurate secondary test in the laboratory. However, conducting the preliminary test using the Cipkowski device may contaminate that part of the specimen exposed to the chemicals carried on the preliminary test strips. In the past, this problem has been addressed by taking multiple separate specimens or being forced to take specimens removed in time from when the original specimen was taken. One can easily appreciate that the taking of a subsequent specimen after a prolonged period allows for changes in the physiology of the test subject. For example, a person suspected of taking drugs can cease drug use whereupon tests taken days later may not turn up positive. In order to avoid taking multiple specimens at potentially far removed times, it is most desirable to perform the confirmatory test on the fluid specimen originally supplied.
Devices such as that disclosed in Ng et al., U.S. Pat. No. 6,726,879 attempt of divide the sample into two separate portions. The first portion is for the preliminary screening test, and the second portion is for securely preserving part of the specimen for transport to a lab for later confirmatory testing. In this way, the first portion can be subjected to the test strips without contaminating the second portion. These devices can be bulky, complicated to operate and costly to manufacture. Manufacturing cost should be kept at a minimum when the device is intended to be disposable.
The device of Guirguis U.S. Pat. No. 6,277,646 provides a movable fluid releasing element which can be driven by the screwing on of the device lid. This allows greater control of the initiation of the preliminary screening test. However, increased manufacturing costs can be expected in forming the frangible wall feature, and using additional components such as the additional bottom wall. Additional costs can be expected because of the detailed and careful assembly required in order to not damage the frangible wall.
In many devices it can be difficult to ensure that the device provides the necessary amount or aliquot of fluid for preliminary testing while also preserving an adequate amount for later confirmatory testing.
The devices disclosed in the above-cited references allow the test to be initiated a time after the placement of the specimen in the cup. Thus a user can control the initiation of the test. Sometimes however it is advantageous to provide a cup where the test is automatically initiated in a non-controlled manner at the time the specimen is deposited. This can result in a device which is less expensive to manufacture and easier to use. The Ng and Guirguis devices for example are not readily adaptable to non-controlled test initiation use.
For many devices used to detect abused drugs, it is desirable to include an adulteration test which typically can include a plural number of colored patches for assessing whether the concentration of certain adulteration parameters such as pH fall outside their acceptable ranges indicating an adulterant may have been added to fool the preliminary test into recording a false negative. Cups which can be readily adapted to include an adulteration test are therefore desirable.
Increasingly, preliminary screening tests are being performed and evaluated by relatively unskilled technicians or even the general public. Therefore, the device needs to be relatively simple to operate to ensure adequate exposure of the preliminary test strips and to provide more consistent results.
Therefore there is a need for a specimen test cup which addresses some or all of the above identified inadequacies.